Glutathione pathway enzymes (GSH pathway enzymes)

Glutathione pathway enzymes comprise a critical network of proteins responsible for the biosynthesis, maintenance, and utilization of glutathione (GSH), the primary intracellular antioxidant and redox buffer (NIH, 2023). Key members of this pathway include glutamate-cysteine ligase (GCL), glutathione synthetase (GSS), glutathione peroxidase (GPX), glutathione reductase (GSR), and glutathione S-transferase (GST) (Wikipedia, 2024). These enzymes collectively regulate cellular redox homeostasis, protect against oxidative damage from reactive oxygen species (ROS), and facilitate the detoxification of xenobiotics and metabolic byproducts (NIH, 2022). In oncology, the upregulation of glutathione pathway enzymes is a well-documented mechanism of resistance to chemotherapy and radiation, as cancer cells utilize elevated GSH levels to neutralize therapeutic agents (PubMed, 2005). Consequently, inhibitors like buthionine sulfoximine (BSO) and various GST inhibitors have been investigated to sensitize tumors to treatment (NIH, 2023). Conversely, in neurodegenerative and inflammatory diseases, therapeutic efforts often focus on enhancing the activity of these enzymes or providing precursors like N-acetylcysteine to restore antioxidant capacity and prevent cell death (NIH, 2022).

Other names

Glutathione metabolic pathway enzymesGSH metabolism enzymesGlutathione system enzymesGlutathione-dependent enzymes

Drugs targeting these enzymes typically act by inhibiting glutathione biosynthesis (e.g., GCL inhibition), blocking the detoxification of chemotherapeutics (e.g., GST inhibition), mimicking antioxidant enzyme activity (e.g., GPX mimetics), or inhibiting the recycling of oxidized glutathione (e.g., GSR inhibition).